Smile is like a secret love note

Archive for the ‘Unix’ Category

Remove ^M from file in unix file

This note is dedicated to my chubby hubby that keep asking me how to remove ^M in a file.

UNIX treats the end of line differently than other operating systems. Normally CTRL-M character is visibly displayed at the end of each line as ^M if the file is not transfered in binary mode (this is why I always prefer SFTP instead of FTP).

In vi, to remove the ^M do as following :

:%s/^V^M//g

^V is a CONTROL-V character
^M is a CONTROL-M.

So it will look like this:

:%s/^M//g

%s is a basic search and replace command in vi.
The g is use for search and replace globally (all occurrences).

with Solaris you can just do (heard HPUX has the command “dos2ux” instead of dos2unix):

dos2unix <dos file> <unix file>

You can also use the octal representatiion of ^M:

tr -d ‘\015\032′ < file

Tags: ascii, binary, dos, vi, ^M

semaphores and shared memory settings

shmsys:shminfo_shmmax
Maximum shared memory segment size

shmsys:shminfo_shmmin
Minimum shared memory segment size

shmsys:shminfo_shmmni
Number of shared memory identifiers

shmsys:shminfo_shmseg
Number of segments, per process

semsys:seminfo_semmap
Number of entries in the semaphore map

semsys:seminfo_semmni
Number of semaphore identifiers

semsys:seminfo_semmns
Number of semaphores in the system

semsys:seminfo_semmsl
Maximum number of semaphores, per ID

semsys:seminfo_semmnu
Number of processes using the undo facility

semsys:seminfo_semume
Maximum number of undo structures per process

Tags: semaphores, setting, shared memory, shminfo, shmsys, Unix

Useful vi command – quick guide

Useful vi Commands

Cut/Paste Commands:

x	delete one character (destructive backspace)
dw	delete the current word (Note: ndw deletes n numbered words)
dd	delete the current line (Note: ndd deletes n numbered lines)
D	delete all content to the right of the cursor
d$	same as above
:u	undo last command
p,P	paste line starting one line below/above current cursor location
J	combine the contents of two lines
"[a-z]nyy	yank next n lines into named buffer [a-z]
"[a-z]p/P	place the contents of selected buffer below/above the current line